Between 2011 and 2016, there has actually been a gradual increase in compliance with speed limits for most vehicles on most roads.

Nevertheless, the figures indicate that 46 per cent of drivers exceeded the speed limit on motorways; 8 per cent exceeded the speed limit on national single carriageways; and 53 per cent exceeded the speed limit on 30mph roads.

It was also found that 15 per cent of drivers exceeded the 20mph limit by more than 10mph.

“The main problem is clearly getting drivers to comply on the ever increasing number of roads in our towns and cities with a 20mph limit.

“IAM RoadSmart have always felt that blanket 20mph limits, enforced by signposts only, are simply not enough to convey the reason for slowing down to drivers. Targeting the worst locations with traffic calming and other engineering features is a much more effective way to make 20mph limits self-enforcing. Speed limits on roads with consistent compliance problems need to be reviewed more frequently.

“We must all work to make it easy to stick to the speed limit and our main concern is that widespread confusion over 20mph may be undermining a more general trend to slow down.”